Abstract: An optical system for radiation in the EUV wavelength range, in particular a projection exposure apparatus, having at least one vacuum vessel, including: at least one EUV-reflective optical element arranged in an optical path, and a holder which includes at least one sample element, the sample element having an optical surface which is exposed to incident EUV-radiation outside of the optical path, the sample element being sensitive to chemical alterations under influence of the incident EUV-radiation which also affect the optical element. The optical system further includes at least one detection unit for online detection of the contamination status of the sample element during exposure of the sample element to the incident EUV-radiation.

Abstract: An extreme ultra-violet lithographic apparatus for imaging a pattern onto a substrate includes a radiation system constructed and arranged to provide a beam of an extreme ultra-violet radiation, and an absorber arranged in the beam and constructed and arranged to absorb at least a portion of the radiation beam. The absorber has a volume configured to accommodate a flow of an absorbing gas. The flow is directed in a transverse direction with respect to the beam. The absorber includes a structure having an extreme ultra-violet radiation-transmissive beam entry area and an extreme ultra-violet radiation-transmissive beam exit area. The apparatus also includes a gas inlet actuator array configured to inject the gas into the volume and a gas outlet actuator array arranged to evacuate the gas from the volume.

Abstract: A cleaning arrangement is configured to clean an EUV optic of an EUV lithographic apparatus. The partial radical pressure ranges between 0.1-10 Pa. The cleaning arrangement can be configured inside a cleaning cocoon of the lithographic apparatus for offline cleaning. It can also be configured at particular positions inside the apparatus to clean nearby optics during production. In the pressure range of 0.1-10 Pa the penetration of atomic hydrogen into the optical devices is high, while the recombination to molecular hydrogen and hydrogen consumption is limited.

Abstract: A radiation sensor for use with a lithographic apparatus is disclosed, the radiation sensor comprising a radiation-sensitive material which converts incident radiation of wavelength ?1 into secondary radiation; and sensing means capable of detecting the secondary radiation emerging from said layer.

Abstract: A lithographic apparatus for maskless EUV applications includes an illumination system constructed and arranged to condition a radiation beam and to supply the conditioned radiation beam to a spatial light modulator, a substrate table constructed and arranged to hold a substrate, and a projection system constructed and arranged to project the conditioned radiation beam onto a target portion of the substrate. The illumination system includes a field facet mirror constructed and arranged to define a field of the conditioned radiation beam. The field facet mirror is constructed and arranged to optically match a source of radiation and the illumination system.

Abstract: A method for the removal of a deposition on an optical element of an apparatus including the optical element includes providing an H2 containing gas in at least part of the apparatus includes producing hydrogen radicals from H2 from the H2 containing gas; and bringing the optical element with deposition into contact with at least part of the hydrogen radicals and removing at least part of the deposition. Further, a method for the protection of an optical element of an apparatus including the optical element includes providing a cap layer to the optical element by a deposition process; and during or after use of the apparatus, removing at least part of the cap layer from the optical element in a removal process as described above. The methods can be applied in a lithographic apparatus.

Abstract: A lithographic apparatus is disclosed. The apparatus includes a projection system configured to project a first radiation beam onto a target portion of a substrate, and at least one monitoring device for detecting contamination in a interior space. The monitoring device includes at least one dummy element having at least one contamination receiving surface. In an aspect of the invention, there is provided at least one dummy element which does not take part in transferring a radiation beam onto a target portion of a substrate, wherein it is monitored whether a contamination receiving surface of the dummy element has been contaminated.

Abstract: A lithographic apparatus that includes an illumination system configured to condition a radiation beam. The illumination system includes a plurality of optical components. The apparatus also includes a support constructed to support a patterning device. The patterning device is capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam. The apparatus further includes a substrate table constructed to hold a substrate, and a projection system configured to project the patterned radiation beam onto a target portion of the substrate. The projection system includes a plurality of optical components. The apparatus also includes a contamination measurement unit for measuring contamination of a surface of at least one of the optical components. The contamination measurement unit is provided with a radiation sensor constructed and arranged to measure an optical characteristic of radiation received from the surface.

Abstract: A multi-layered spectral purity filter improves the spectral purity of extreme ultra-violet (EUV) radiation and also collects debris emitted from a radiation source.

Abstract: An optical arrangement, in particular a projection system, illumination system or beam shaping system for EUV lithography, including at least one optical element that is arranged in a beam path of the optical arrangement and that reflects radiation in the soft X-ray- or EUV wavelength range, wherein at least during operation of the optical arrangement at least one of, preferably each of, the reflective optical elements in the beam path, at least at the optical surface, has an operating temperature of approximately 30° C. or more, preferably of approximately 100° C. or more, particularly preferably of approximately 150° C. or more, and even more preferably of approximately 250° C. or more, and wherein the optical design of the at least one reflective optical element is selected such that its optical characteristics are optimised for operation at the operating temperature. Also presented is a method for providing a reflective optical element with such an optical design.

Abstract: A multi-layered spectral purity filter improves the spectral purity of extreme ultra-violet (EUV) radiation and also collects debris emitted from a radiation source.

Abstract: A lithographic system includes a radiation system configured to provide a beam of radiation; an illumination system configured to condition the beam of radiation; a support configured to support a patterning device, the patterning device configured to impart the projection beam with a pattern in its cross-section; a substrate table configured to hold a substrate; a projection system configured to project the patterned beam onto a target portion of the substrate; and transmission adaptor arranged along an optical pathway. The radiation system includes a source configured to generate a beam of radiation. The transmission adaptor adapts an intensity profile as a function of wavelength of the beam of radiation and/or the patterned beam in such a way that the intensity profile equals a predetermined intensity profile.

Abstract: A device manufacturing method includes projecting a patterned beam of radiation through an optics compartment and a channel that provides an open connection between the optics compartment and a substrate compartment onto a substrate, maintaining an ionized flush gas at a higher pressure in the channel than in the substrate compartment and in the optics compartment during the projecting, intercepting particles that emanate from the substrate with the ionized flush gas, pumping the flush gas carrying the intercepted particles from the substrate compartment using a pump coupled to a gas outlet coupled to at least one of the compartments, and establishing an electrical potential difference between a wall of the channel and the outlet and/or a rotor of the pump so that the outlet and/or the rotor of the pump attracts positively charged ions that stem from the flush gas in the channel.

Abstract: A method to clean optical elements of an apparatus, the apparatus being configured to project a beam of radiation onto a target portion of a substrate, the apparatus comprising a plurality of optical elements arranged in sequence in the path of the radiation beam, wherein the cleaning method comprises: cleaning one or more second optical elements of the sequence, which receive one or more relatively low second radiation doses during operation of the apparatus, utilizing cumulatively shorter cleaning periods than one or more first optical elements of the sequence that receive one or more first radiation doses during operation of the apparatus, a second radiation dose being lower than each relatively high first radiation dose.

Abstract: A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Abstract: A method for the removal of a deposition on an optical element of an apparatus including the optical element includes providing an H2 containing gas in at least part of the apparatus includes producing hydrogen radicals from H2 from the H2 containing gas; and bringing the optical element with deposition into contact with at least part of the hydrogen radicals and removing at least part of the deposition. Further, a method for the protection of an optical element of an apparatus including the optical element includes providing a cap layer to the optical element by a deposition process; and during or after use of the apparatus, removing at least part of the cap layer from the optical element in a removal process as described above. The methods can be applied in a lithographic apparatus.

Abstract: A lithographic apparatus includes a radiation source configured to emit radiation to form a radiation beam, the radiation being of a type which can create plasma in a low pressure environment in the apparatus, and an optical component configured to condition the radiation beam, impart the conditioned radiation beam with a pattern in its cross-section to form a patterned radiation beam, project the patterned radiation beam onto a target portion of a substrate, and/or to detect radiation. The optical component is provided with a plasma quenching structure, the plasma quenching structure being configured to provide electron-ion recombination in, on and/or near the optical component.

Abstract: A lithographic apparatus includes a radiation source and an object with a first surface which is configured to retain metal contaminants. This surface has the function of a getter. The first surface is arranged substantially outside the region traversed by the radiation beam generated by the radiation source during lithographic processing. The first surface may further be used to retain volatile contaminants generated in a cleaning method.

Abstract: A lithographic apparatus is arranged to project a beam from a radiation source onto a substrate. The apparatus includes an optical element in a path of the beam, a gas inlet for introducing a gas into the path of the beam so that the gas will be ionized by the beam to create electric fields toward the optical element, and a gas source coupled to the gas inlet for supplying the gas. The gas has a threshold of kinetic energy for sputtering the optical element that is greater than the kinetic energy developed by ions of the gas in the electric fields.

Abstract: A radiation system for generating a beam of radiation is disclosed. The radiation system includes a pulsed EUV source for generating EUV radiation, and a spectral filter mounted in front of the EUV source for selectively passing a spectral range of a beam of EUV radiation from the EUV source. The spectral filter is mounted on a movable mount configured to be moved in synchronicity with the pulsed EUV source to prevent debris traveling from the EUV source from impacting the spectral filter. Accordingly, the spectral filter is kept substantially free from contamination by the debris.